diff --git a/Gemfile b/Gemfile
index bdfff856..e0a4364c 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,17 +3,32 @@ source 'https://rubygems.org'
 # Specify your gem's dependencies in active_model_serializers.gemspec
 gemspec
 
-gem "minitest"
+version = ENV['RAILS_VERSION'] || '4.2'
 
-version = ENV["RAILS_VERSION"] || "4.2"
-
-if version == "master"
-  gem "rails", github: "rails/rails"
-
-  # ugh https://github.com/rails/rails/issues/16063#issuecomment-48090125
-  gem "arel", github: "rails/arel"
+if version == 'master'
+  gem 'rack', github: 'rack/rack'
+  git 'https://github.com/rails/rails.git' do
+    gem 'railties'
+    gem 'activesupport'
+    gem 'activemodel'
+    gem 'actionpack'
+    # Rails 5
+    gem 'actionview'
+  end
+  # Rails 5
+  gem 'rails-controller-testing', github: 'rails/rails-controller-testing'
 else
-  gem "rails", "~> #{version}.0"
+  gem_version = "~> #{version}.0"
+  gem 'railties', gem_version
+  gem 'activesupport', gem_version
+  gem 'activemodel', gem_version
+  gem 'actionpack', gem_version
+end
+
+group :test do
+  gem 'activerecord'
+  gem 'sqlite3', platform: :ruby
+  gem 'activerecord-jdbcsqlite3-adapter', platform: :jruby
 end
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
diff --git a/active_model_serializers.gemspec b/active_model_serializers.gemspec
index eff27ca9..de385a97 100644
--- a/active_model_serializers.gemspec
+++ b/active_model_serializers.gemspec
@@ -4,26 +4,47 @@ $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require 'active_model/serializer/version'
 
 Gem::Specification.new do |spec|
-  spec.name          = "active_model_serializers"
+  spec.name          = 'active_model_serializers'
   spec.version       = ActiveModel::Serializer::VERSION
-  spec.authors       = ["Steve Klabnik"]
-  spec.email         = ["steve@steveklabnik.com"]
+  spec.platform      = Gem::Platform::RUBY
+  spec.authors       = ['Steve Klabnik']
+  spec.email         = ['steve@steveklabnik.com']
   spec.summary       = %q{Conventions-based JSON generation for Rails.}
   spec.description   = %q{ActiveModel::Serializers allows you to generate your JSON in an object-oriented and convention-driven manner.}
-  spec.homepage      = "https://github.com/rails-api/active_model_serializers"
-  spec.license       = "MIT"
+  spec.homepage      = 'https://github.com/rails-api/active_model_serializers'
+  spec.license       = 'MIT'
 
   spec.files         = `git ls-files -z`.split("\x0")
-  spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
-  spec.require_paths = ["lib"]
+  spec.require_paths = ['lib']
 
-  spec.add_dependency "activemodel", ">= 4.0"
+  spec.required_ruby_version = '>= 1.9.3'
 
-  spec.add_development_dependency "rails", ">= 4.0"
-  spec.add_development_dependency "bundler", "~> 1.6"
-  spec.add_development_dependency "timecop", ">= 0.7"
-  spec.add_development_dependency "rake"
-  spec.add_development_dependency "kaminari"
-  spec.add_development_dependency "will_paginate"
+  rails_versions = '>= 4.0'
+  spec.add_runtime_dependency 'activemodel', rails_versions
+    # 'activesupport', rails_versions
+    # 'builder'
+
+  spec.add_runtime_dependency 'actionpack', rails_versions
+    # 'activesupport', rails_versions
+    # 'rack'
+    # 'rack-test', '~> 0.6.2'
+
+  spec.add_runtime_dependency 'railties', rails_versions
+    # 'activesupport', rails_versions
+    # 'actionpack', rails_versions
+    # 'rake', '>= 0.8.7'
+
+  # 'activesupport', rails_versions
+    # 'i18n,
+    # 'tzinfo'
+    # 'minitest'
+    # 'thread_safe'
+
+  # Soft dependency for pagination
+  spec.add_development_dependency 'kaminari'
+  spec.add_development_dependency 'will_paginate'
+
+  spec.add_development_dependency 'bundler', '~> 1.6'
+  spec.add_development_dependency 'timecop', '>= 0.7'
 end
diff --git a/lib/active_model/serializer.rb b/lib/active_model/serializer.rb
index a9f0e756..6e6833bb 100644
--- a/lib/active_model/serializer.rb
+++ b/lib/active_model/serializer.rb
@@ -70,7 +70,7 @@ module ActiveModel
       ActiveModelSerializers.silence_warnings do
         define_method key do
           object.read_attribute_for_serialization(attr)
-        end unless respond_to?(key, false) || _fragmented.respond_to?(attr)
+        end unless (key != :id && method_defined?(key)) || _fragmented.respond_to?(attr)
       end
     end
 
diff --git a/lib/active_model/serializer/association.rb b/lib/active_model/serializer/association.rb
index af1cb914..bca03665 100644
--- a/lib/active_model/serializer/association.rb
+++ b/lib/active_model/serializer/association.rb
@@ -7,7 +7,7 @@ module ActiveModel
     # @param [Hash{Symbol => Object}] options
     #
     # @example
-    #  Association.new(:comments, CommentSummarySerializer, embed: :ids)
+    #  Association.new(:comments, CommentSummarySerializer)
     #
     Association = Struct.new(:name, :serializer, :options) do
 
diff --git a/lib/active_model/serializer/lint.rb b/lib/active_model/serializer/lint.rb
index 97ffcd7f..bf3b7a37 100644
--- a/lib/active_model/serializer/lint.rb
+++ b/lib/active_model/serializer/lint.rb
@@ -36,7 +36,17 @@ module ActiveModel::Serializer::Lint
     # Typically, it is implemented by including ActiveModel::Serialization.
     def test_read_attribute_for_serialization
       assert_respond_to resource, :read_attribute_for_serialization, "The resource should respond to read_attribute_for_serialization"
-      assert_equal resource.method(:read_attribute_for_serialization).arity, 1
+      actual_arity = resource.method(:read_attribute_for_serialization).arity
+      if defined?(::Rubinius)
+        #  1 for def read_attribute_for_serialization(name); end
+        # -2 for alias :read_attribute_for_serialization :send for rbx because :shrug:
+        assert_includes [1, -2], actual_arity, "expected #{actual_arity.inspect} to be 1 or -2"
+      else
+        # using absolute value since arity is:
+        #  1 for def read_attribute_for_serialization(name); end
+        # -1 for alias :read_attribute_for_serialization :send
+        assert_includes [1, -1], actual_arity, "expected #{actual_arity.inspect} to be 1 or -1"
+      end
     end
 
     # Passes if the object responds to <tt>as_json</tt> and if it takes
@@ -68,7 +78,7 @@ module ActiveModel::Serializer::Lint
     end
 
     # Passes if the object responds to <tt>cache_key</tt> and if it takes no
-    # arguments.
+    # arguments (Rails 4.0) or a splat (Rails 4.1+).
     # Fails otherwise.
     #
     # <tt>cache_key</tt> returns a (self-expiring) unique key for the object,
@@ -76,7 +86,11 @@ module ActiveModel::Serializer::Lint
     # It is not required unless caching is enabled.
     def test_cache_key
       assert_respond_to resource, :cache_key
-      assert_equal resource.method(:cache_key).arity, 0
+      actual_arity = resource.method(:cache_key).arity
+      # using absolute value since arity is:
+      #   0 for Rails 4.1+, *timestamp_names
+      #  -1 for Rails 4.0, no arguments
+      assert_includes [-1, 0], actual_arity, "expected #{actual_arity.inspect} to be 0 or -1"
     end
 
     # Passes if the object responds to <tt>id</tt> and if it takes no
diff --git a/lib/active_model_serializers.rb b/lib/active_model_serializers.rb
index 01c23e5f..8b90ba7a 100644
--- a/lib/active_model_serializers.rb
+++ b/lib/active_model_serializers.rb
@@ -10,22 +10,20 @@ module ActiveModelSerializers
   end
 
 end
+
 require 'active_model'
-require 'active_model/serializer/version'
+require 'action_controller'
+
 require 'active_model/serializer'
 require 'active_model/serializable_resource'
+require 'active_model/serializer/version'
 
-begin
-  require 'active_model/serializer/railtie'
-  require 'action_controller'
-  require 'action_controller/serialization'
-
-  ActiveSupport.on_load(:action_controller) do
-    include ::ActionController::Serialization
-    ActionDispatch::Reloader.to_prepare do
-      ActiveModel::Serializer.serializers_cache.clear
-    end
+require 'action_controller/serialization'
+ActiveSupport.on_load(:action_controller) do
+  include ::ActionController::Serialization
+  ActionDispatch::Reloader.to_prepare do
+    ActiveModel::Serializer.serializers_cache.clear
   end
-rescue LoadError
-  # rails not installed, continuing
 end
+
+require 'active_model/serializer/railtie'
diff --git a/test/fixtures/active_record.rb b/test/fixtures/active_record.rb
new file mode 100644
index 00000000..ab3e4d85
--- /dev/null
+++ b/test/fixtures/active_record.rb
@@ -0,0 +1,57 @@
+require 'active_record'
+
+ActiveRecord::Base.establish_connection(adapter: 'sqlite3', database: ':memory:')
+ActiveRecord::Schema.define do
+  create_table :posts, force: true do |t|
+    t.string :title
+    t.text :body
+    t.references :author
+    t.timestamps null: false
+  end
+  create_table :authors, force: true do |t|
+    t.string :name
+    t.timestamps null: false
+  end
+  create_table :comments, force: true do |t|
+    t.text :contents
+    t.references :author
+    t.references :post
+    t.timestamp null: false
+  end
+end
+
+module ARModels
+  class Post < ActiveRecord::Base
+    has_many :comments
+    belongs_to :author
+  end
+
+  class Comment < ActiveRecord::Base
+    belongs_to :post
+    belongs_to :author
+  end
+
+  class Author < ActiveRecord::Base
+    has_many :posts
+  end
+
+  class PostSerializer < ActiveModel::Serializer
+    attributes :id, :title, :body
+
+    has_many :comments
+    belongs_to :author
+    url :comments
+  end
+
+  class CommentSerializer < ActiveModel::Serializer
+    attributes :id, :contents
+
+    belongs_to :author
+  end
+
+  class AuthorSerializer < ActiveModel::Serializer
+    attributes :id, :name
+
+    has_many :posts
+  end
+end
diff --git a/test/fixtures/poro.rb b/test/fixtures/poro.rb
index 0c0e3a58..815205c4 100644
--- a/test/fixtures/poro.rb
+++ b/test/fixtures/poro.rb
@@ -134,10 +134,11 @@ end
 
 AuthorSerializer = Class.new(ActiveModel::Serializer) do
   cache key:'writer', skip_digest: true
-  attributes :id, :name
+  attribute :id
+  attribute :name
 
-  has_many :posts, embed: :ids
-  has_many :roles, embed: :ids
+  has_many :posts
+  has_many :roles
   has_one :bio
 end
 
diff --git a/test/serializers/association_macros_test.rb b/test/serializers/association_macros_test.rb
index f99e1980..30202f4a 100644
--- a/test/serializers/association_macros_test.rb
+++ b/test/serializers/association_macros_test.rb
@@ -6,7 +6,7 @@ module ActiveModel
       AuthorSummarySerializer = Class.new
       class AssociationsTestSerializer < Serializer
         belongs_to :author, serializer: AuthorSummarySerializer
-        has_many :comments, embed: :ids
+        has_many :comments
         has_one :category
       end
 
@@ -21,7 +21,7 @@ module ActiveModel
       end
 
       def test_has_many_defines_reflection
-        has_many_reflection = HasManyReflection.new(:comments, embed: :ids)
+        has_many_reflection = HasManyReflection.new(:comments, {})
 
         assert_includes(@reflections, has_many_reflection)
       end
diff --git a/test/serializers/associations_test.rb b/test/serializers/associations_test.rb
index b7b77cf9..bfc1b40c 100644
--- a/test/serializers/associations_test.rb
+++ b/test/serializers/associations_test.rb
@@ -52,13 +52,13 @@ module ActiveModel
 
           case key
           when :posts
-            assert_equal({ embed: :ids }, options)
+            assert_equal({}, options)
             assert_kind_of(ActiveModel::Serializer.config.array_serializer, serializer)
           when :bio
             assert_equal({}, options)
             assert_nil serializer
           when :roles
-            assert_equal({ embed: :ids }, options)
+            assert_equal({}, options)
             assert_kind_of(ActiveModel::Serializer.config.array_serializer, serializer)
           else
             flunk "Unknown association: #{key}"
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 115972d6..7df3b118 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -34,8 +34,10 @@ require 'support/stream_capture'
 
 require 'support/rails_app'
 
-require 'fixtures/poro'
-
 require 'support/test_case'
 
 require 'support/serialization_testing'
+
+require 'fixtures/active_record'
+
+require 'fixtures/poro'